• 7/14/2005
  • Atlanta, GA
  • American Cancer Society
  • CA Cancer J Clin 2005; 55:205-206

Vitamin E supplementation does not reduce the incidence of cancer or major cardiovascular events, according to a recent article in JAMA (2005;293:1338–1347). In fact, high doses appear to actually raise the risk of heart failure in certain people, a team of Canadian, US, and British researchers reported.

The findings come from a trial known as HOPE-TOO (Heart Outcomes Prevention Evaluation–The Ongoing Outcomes). The study was a continuation of an earlier trial comparing vitamin E and ramipril in patients at high risk of cardiovascular events because of diabetes, peripheral or coronary arterial disease, or other cardiovascular disease risk factors. Participants in HOPE-TOO were randomized to take either 400 IU of vitamin E daily or a placebo.

The researchers examined overall cancer cases and deaths and found no significant differences between the two groups. Then they looked at specific cancers that previous studies suggested might be prevented by vitamin E: prostate, lung, oral, colorectal, breast, and melanoma. Even for these cancers, no significant difference was seen between the groups.

When the researchers examined heart disease incidence, they found no differences between the groups for heart attacks, stroke, unstable angina, and several other types of heart problems. However, people on vitamin E were more likely to develop heart failure.

No other study of vitamin E has looked at heart failure; the researchers suggest reviews of previous research be done to look for similar links.

The study isn’t the first to find no overall cancer or heart benefits from vitamin E, but some experts say it may be the last word on the subject.

In an accompanying editorial, University of Washington Professors B. Greg Brown, MD, PhD, and John Crowley, PhD, say the work “effectively closes the door” on the idea that vitamin E will be of major benefit in preventing cancer or heart disease.

Brown is a Professor in the Division of Cardiology at the University’s medical school. Crowley is a Professor of Biostatistics at the University’s School of Public Health and Community Medicine and a member of the Department of Cancer Research and Biostatistics at Fred Hutchinson Cancer Research Center in Seattle.

The new research, they said, will allow doctors to give patients the following definitive answer to their questions about vitamin E:

“In nearly 68,000 patients studied to date, there is no compelling evidence that higher doses of vitamin E reduce cardiovascular risk or cancer; there are even some hints that vitamin E, in excess of normal daily intake, may slightly increase the risk of ischemic events or heart failure.

“You may hear that vitamin E is a ‘natural’ yet effective way to prevent heart disease or cancer, but this has proven to be a false hope. You should not be misled into neglecting other proven methods of prevention.”

Despite the disappointing results of this study for cancer and heart disease overall, Brown and Crowley note that vitamin E hasn’t been ruled out completely as a helpful substance for some very specific conditions, including certain cancers.

The ongoing Selenium and Vitamin E Cancer Prevention Trial (SELECT), for instance, will follow more than 35,000 men for at least 7 years to help determine whether vitamin E and selenium can protect men against prostate cancer.

In another recent study, -tocopherol, a form of vitamin E, provided no benefit in reducing the risk of a second primary tumor among survivors of Stage I or II head and neck cancers previously treated with radiotherapy. The report in the Journal of the National Cancer Institute (2005;97:481–488) by Isabelle Bairati, MD, PhD, a Professor at the Universite Laval in Quebec, and colleagues from several Canadian and US centers, noted no difference in the likelihood of being free of a second primary tumor after 8 years of follow up between subjects in the vitamin E and placebo groups.

In an accompanying JNCI editorial (2005;97:468–470), two chemoprevention researchers from the MD Anderson Cancer Center offer their perspective on the future of cancer chemoprevention. Edward Kim, MD, Assistant Professor, Department of Thoracic/Head & Neck Medical Oncology, and Waun Ki Hong, MD, Professor and Chair of the same department, note that although results of many chemoprevention trials using vitamins such as -tocopherol have been disappointing, it is important to investigate other chemoprevention strategies. Kim and Hong suggest that the next generation of chemoprevention trials will use novel molecularly targeted agents in subjects stratified by risk factors and biomarkers.